1. Field of the Invention
The present invention relates to digital video data links and, more specifically, to circuits and methods for linking multiple video display devices.
2. Description of Related Art
Digital display technology for video data streams is being widely adopted within the personal computer (PC) and consumer electronics (CE) industries. The VESA DisplayPort Standard, Version 1, Revision 1a of Jan. 11, 2008 for video data links (hereinafter DisplayPort, or DP), incorporated herein by reference in its entirety, is an example of a standard that may be used for transmission of video data streams. With the advent of digital video signals, the issue of extending the length of transmission links has become more relevant, particularly in applications that make use of multiple video display devices associated with a common video data source.
Current analog video circuits use repeater devices to extend the transmission distance of video data links. However, analog repeaters lack a clock recovery mechanism because of the nature of analog video signals.
Other approaches for extending digital data transmission links include the implementation of optical data transfer in order to extend the transmission distance of the video signal. However, optical data transfer circuits have a high implementation cost, due to the up-front and maintenance cost of components. In addition, opto-electronic conversion devices and protocols are required at both ends of the transmission link, increasing the level of circuit complexity. Furthermore, optical data transfer may not be adapted to digital video protocols commonly used in industry, such as the DP standards above. This imposes the need for extra circuitry and data processing at every node in the optical data transmission link.
Therefore, there is a need for easily adaptable digital video relay circuits that may extend transmission links to multiple display devices.